Regeneration of tomato
Seed dormancy
Fresh seeds may germinate irregularly. After storing the seeds for about half a year, the germination becomes normal.
Vernalization
None.
Sowing
Before sowing seeds are disinfected (see pepper), to avoid infection with Tobacco Mosaic Virus (TMV), and other viruses. Seeds are sown in seed trays at 23°C, generally between January and March, but it is possible to sow until July. After 10-14 days the seedlings are transplanted to rockwool blocks (12x12 cm) at a temperature of 23/20°C day/night.
Planting
About 7 weeks after sowing the plants in the Rockwool blocks are placed on Rockwool bags at a distance of 50 cm in the row and alternating 60 and 100 cm between the rows, at a temperature of 23/20°C day/night. The plants are grown along wires (1 stem per plant for the indeterminate types). Plants are pruned regularly, taking precautions to prevent virus transmission. During regeneration, plants are tested twice for occurrence of Pepino Mosaic Virus. About 2.5 months after sowing, the plants start to flower. To improve seed set the racemes are touched with a vibrator, improving the pollination.
Per accession seven plants are used for regeneration. For cross-pollinating wild species or heterogeneous accessions up to 14 plants are used. For these species a pollen-mixture of all plants in the accession is used for hand pollination.
Harvesting
About 5 months after sowing, the fruits start to ripen. Per plant, 10 or more ripe fruits are harvested.
Pest and disease control
Biological control
- Spider mites with Phytoseiulus persimilis
- Thrips with Phytoseiulus persimilis and Orius laevigatus
- Whitefly with Aphidius colemani
- Aphids with Encarsia formosa
Pesticide treatments
Non-preventive:
- Spider mites, in case biological control is not effective.
During regeneration the plants are checked visually for diseases by the Netherlands Inspection Service for Horticulture (Naktuinbouw). In case of doubt, the plants are tested to determine the disease. Infected plants are removed.